Tail rotor fears ground Sea Kings

Page Tools

Emergency flights by navy Sea King helicopters have been banned
after military investigators suggested a broken tail rotor control
may have caused the helicopter crash on the Indonesian island of
Nias that killed nine people last month.

The preliminary investigation report on the disaster, released
yesterday, found no evidence the helicopter crashed "under
controlled flight" or that weather played a part - pointing towards
mechanical failure and not crew error as the cause of the
crash.

In response, Maritime Commander Rear Admiral Rowan Moffitt
extended a ban on Sea King flights and ordered all six remaining
helicopters to undergo a complete mechanical inspection.

He announced that a full board of inquiry, including a civilian
aviation expert, would hold public hearings on the accident.

Inspectors would examine the six helicopters' flight control
systems after investigators at the crash site found two elements of
the wire and hydraulic control system tail rotor were detached,
Admiral Moffitt said.

Military experts confirmed that loss of tail rotor control in
the Sea King would cause the helicopter to spin out of control and
probably crash.

The crash of the 31-year-old Sea King operating from HMAS
Kanimbla during earthquake relief operations last month led to the
rest of the navy's fleet being grounded, except in emergencies.
Now, no flights would be permitted, Admiral Moffitt said.

He said the crash investigators failed to find components of the
flight control system.

"The team inspected the mechanical flight control run from the
cockpit through to the tail rotor gearbox. Two components of the
flight control run which are normally connected were found to be
detached from one another. Several parts of the hardware that
normally connect those two items together haven't been located," he
said.

But he said those components might have been destroyed on impact
or in the subsequent fire.

Admiral Moffitt said recovered flight data and cockpit voice
recorders had not identified the cause of the crash, the navy's
worst aviation disaster.

Initial examination had found no evidence of engine failure or
main rotor blade failure. Further data was being gathered, he
said.

"The team's work is a long way from finished," Admiral Moffitt
said. "We need to avoid jumping to conclusions."

Admiral Moffitt said the board of inquiry had interviewed
witnesses in Indonesia and would hold hearings in Australia.

The program director with the Australian Strategic Policy
Institute, Aldo Borgu, said initial findings could indicate a fault
with the individual helicopter, rather than all the Sea Kings.

However, he said it was a sensible precaution to ground the
entire fleet.